The figure typically reported as a "recycling rate" is usually the proportion of materials collected for recycling. Bales of PET collected for recycling often contain materials such as polypropylene caps, base cups, labels and glue, and other contaminants, which are then weighed and included in the PET recycling rate.

The "Utilization Rate" shown on this page is a more accurate depiction of how much PET actually gets recycled. It measures the amount of "clean PET flake" yielded once the contaminants have been removed.